1.1 Earth's Crust in Motion

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Vocabulary

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Geologists: scientists who study the forces that make and shape the Earth
Geology: the study of planet Earth
Constructive forces: forces that build up landmasses like mountains
Destructive forces: forces that slowly wear away mountains and surface such as what an ocean does
Continents: seven large landmasses on earth
Seismic waves: waves that move through the Earth's interior
Pressure: force pushing on a surface or area
Crust: layer of rock that makes up the Earth's outer skin
Basalt: dark, dense rock that forms the oceanic crust
Granite: rock with larger crystals that is less dense than basalt and makes up the continental crust
Mantle: layer of hot rock below the crust
Lithosphere: means "stone" and is the mantle and crust together
Asthenosphere: means "weak" soft rock material that can flow slowly
Outer core: layer of molten metal that surrounds the inner core
Inner core: dense ball of solid metal

Outline

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Science of Geology

• studying surface changes
  • surface always changing
• finding indirect evidence
  • cannot see inside earth
  • use seismic waves
    • speed of waves tells the material

Center of the Earth

• temperature
  • surface rock is cool
  • 20 meters/warmer
  • every 40 meters 1 degree Celsius hotter
    • boy that's hot
• pressure
  • deeper you the greater the pressure

The crust

• you can find rocks and mountains
• crust ranges from 5 to 40 kilometers thick
• crust beneath ocean is oceanic crust

The mantle

• lithosphere averages about 100 kilometers thick

The core

• outer core
  • behaves like a thick liquid
• inner core
  • extreme pressure squeezes the atoms of iron and nickel so much that they cannot spread out and become liquid

Earth's magnetic field

• currents in the outer core forces the inner core to spin
• inner core spins faster than the rest of the planets